Chris Clarke gave the following explanation of one method of completing
a sextuple peel on the Nottingham Croquet News Group. I have added images
to Chris' commentary. [IRP]

One of the great enjoyments of croquet is finding out how to do things by
trial and error yourself. However, if this method is too slow, I hope the explanation
beneath is of some help, although I am sure that someone in the World top 10
would be able to give much better detail.

A Sextuple
Leave is shown opposite. Assume the opponent (Black
and Blue) miss your ball (try to leave only one open) near third
corner.

1-back Peel

Hit opponent and stop-shot into the lawn (say past hoop 3) (A),
getting a rush to hoop 2 (some people may prefer south boundary) (B).

Rush peelee to hoop 2 and take off to pioneer at hoop 1 (I usually
try to rush into peeling position at 1-back and peel going to pioneer
at 1). Make hoop 1 and rush to ball near 3 (C). Position
hoop 3 pioneer at hoop 3 or slightly west, getting rush on other ball
to hoop 2 (D). Croquet escape ball to 3-4 yards southeast
of hoop 2 (E), obtaining rush on peelee. Approach hoop
2 sending peelee in front of 1-back (F).

Run 2 and hit peelee. Peel 1-back, sending peelee down to 2-back and
obtaining northwards rush on escape ball. Rush to comfortable position
(G) to be able to send to hoop 4 (H)(or
slightly west) getting a rush to hoop 3 on pioneer.

Make 3 and rush so that you can send out an escape ball (see ** below),
whilst obtaining rush on peelee to 2-back (I)

** If you have peeled 1-back to close to 2-back and are confident of
rushing peelee in front of 2-back and at least jawsing going to your
hoop 4 pioneer, you can send your escape ball 4 yards east of 2-back
(but not blocking path to hoop 4 pioneer). If you are not confident of
jawsing before hoop 4 (this is more likely), then send your escape ball
to a position where you will get a good rush to hoop 5 if you play a
stop shot peel from 2 feet (J).

2-back Peel

Assuming you are not able to peel before 4, take off from peelee leaving
it close to 2-back (K), going to your hoop 4 pioneer.
Make hoop 4 and rush back to near corner 1 (L), in a
position where you can send a pioneer to hoop 6 (not beyond), obtaining
a rush on peelee to peeling position (M). Peel 2-back
obtaining a rush on your escape ball to hoop 5 (N)

3-back Peel

Make hoop 5 and get a rush to corner 1 (O)(most places
on A-baulk are ok). Send pioneer towards 1-back (I prefer it 2-3 yards
south), getting a rush on peelee to 3-back. Rush peelee to 3-back (P)
and take off to hoop 6 (try peel if you play good rush). If rushing peelee
to 3-back is not possible, you will have to croquet peelee to 3-back
going to hoop 6 pioneer.

4-back Peel

Make 1-back, obtaining eastwards rush (T). You want
to end up with the peelee in front of 4-back with your escape ball a
couple of feet to the side. The exact combination of strokes to achieve
this will depend upon how far you have peeled 3-back and what shots you
are good at (U). Take off from peelee, leaving it near
to 4-back (1 inch in front of the hoop is handy), going to your pioneer
at 2-back.

Penult Peel

Make 3-back obtaining rush to 3rd corner or vicinity (X).
Send ball to 2 yards south of penult and off the line of penult and rover,
getting rush on peelee to penult (Y). Rush in front
of penult and peel obtaining rush to 4-back (Z). Finish
with single peel. If you don't rush in front of penult, finish with straight
double. Sorry, I can't tell you how to do a straight double, because
if Mulliner were to find out, he'd be much more difficult to beat, and
he's the only player I can beat nowadays!